A cutting device for a processed tape known in the art includes a first cutting mechanism which has a full-cut function, a second cutting mechanism which has a half-cut function, a single cutter motor which provides driving power for these cutting mechanisms, and a driving mechanism which drives the first cutting mechanism and the second cutting mechanism by the driving power of the cutter motor (see Japanese Patent No. 4,539,620). The second cutting mechanism has a receiver and a movable cutter which moves close to and away from the receiver. According to this type of cutting device, the receiver abuts a pair of projections provided at both ends of the movable cutter to produce a clearance having a length equivalent to the thickness of a released tape between the receiver and the movable cutter. In this condition, the cutting device cuts only the main tape of the processed tape (half cutting).
At the time of half cutting, the actuation of the cutter motor for cutting is continued for a period longer by certain seconds than the time required for the abutment between the receiver and the projections of the movable cutter so as to perform secure cutting and thereby achieve desirable half cutting. In this case, a certain level or higher of torque is not applied to the cutter motor by the function of a torque limiter inserted into a transmission mechanism of the driving mechanism. This torque limiter has a pair of gears and a coil spring interposed between the gears.
According to the cutting device disclosed in Japanese Patent No. 4,539,620, the cutting force of a half cutter (second cutting mechanism) is controlled by using the torque limiter which chiefly utilizes the force of the coil spring. In this case, the cutting speed of the half cutter is variable due to the sliding load of the driving mechanism and the precision errors of the torque limiter. More specifically, the control value for the period of the half-cut operation is variable due to the instability of the time required for the abutment between the projections of the half cutter and the receiver. This condition prevents stabilization of the cutting period for the half cutting, and produces problems such as cutting of the main tape and insufficient cutting of the released tape.